JP4806968B2 - Cold cathode field emission display - Google Patents

Description

  The present invention relates to a method for maintaining the characteristics of an antistatic film formed on the surface of a spacer provided in a cold cathode field emission display.

  As an image display device that can replace the mainstream cathode ray tube (CRT), various types of flat display devices have been studied. Examples of such a flat display device include a liquid crystal display device (LCD), an electroluminescence display device (ELD), and a plasma display device (PDP). Development of a cold cathode field emission display device (hereinafter sometimes abbreviated as a display device) incorporating a cathode panel provided with a cold cathode field electron emission device (hereinafter sometimes abbreviated as a field emission device). Are also attracting attention from the viewpoints of high resolution, high brightness color display, and low power consumption.

Generally, in a display device, a cathode panel CP having a plurality of field emission elements and an anode panel having a phosphor layer that emits light when excited by collision with electrons emitted from the field emission elements are in a high vacuum (for example, 1 × 10 ⁻³ Pa or less). Here, the cathode panel CP has electron emission regions corresponding to the respective pixels arranged in a two-dimensional matrix, and each electron emission region is provided with one or a plurality of field emission elements. Examples of field emission devices include Spindt type, flat type, edge type, and planar type.

  As an example, a conceptual partial end view of a display device having a Spindt-type field emission device is shown in FIG. 1, and a schematic view of a part of the cathode panel CP and the anode panel AP when the cathode panel CP and the anode panel AP are disassembled. A simple exploded perspective view is shown in FIG. The Spindt-type field emission device constituting the display device includes a cathode electrode 11 formed on a support 10, a first insulating layer 12 formed on the support 10 and the cathode electrode 11, and a first insulating layer 12. Formed on the gate electrode 13, a second opening 14B provided in the gate electrode 13, a third opening 14C provided in the first insulating layer 12, and a cathode located at the bottom of the third opening 14C. A conical electron emission portion 15 formed on the electrode 11, a second insulating layer 16 formed on the first insulating layer 12 and the gate electrode 13, and a focusing electrode 17 formed on the second insulating layer 16. And a first opening 14A provided in the second insulating layer 16 and the focusing electrode 17. In FIG. 2, the focusing electrode 17, the second insulating layer 16, and the first opening 14A are not shown.

  Alternatively, FIG. 3 shows a conceptual partial end view of a display device having a so-called flat field emission device having a substantially planar electron emission portion 15A. The field emission device includes a cathode electrode 11 formed on a support 10, a first insulating layer 12 formed on the support 10 and the cathode electrode 11, and a gate electrode formed on the first insulating layer 12. 13, the second opening 14 </ b> B provided in the gate electrode 13, the third opening 14 </ b> C provided in the first insulating layer 12, and the cathode electrode 11 positioned at the bottom of the third opening 14 </ b> C. 15A, the second insulating layer 16 formed on the first insulating layer 12 and the gate electrode 13, the converging electrode 17 formed on the second insulating layer 16, the second insulating layer 16 and the converging The first opening 14 </ b> A provided in the electrode 17 is configured. The electron emission portion 15A is composed of, for example, a large number of carbon nanotubes partially embedded in a matrix.

  In these display devices, the cathode electrode 11 has a strip shape extending in the first direction (for example, the X direction), and the gate electrode 13 has a strip shape extending in the second direction (for example, the Y direction) different from the first direction. (See FIGS. 1 to 3). In general, the cathode electrode 11 and the gate electrode 13 are each formed in a strip shape in a direction in which the projected images of both the electrodes 11 and 13 are orthogonal to each other. An overlapping region where the strip-shaped cathode electrode 11 and the strip-shaped gate electrode 13 overlap is an electron emission region EA, which corresponds to one subpixel. The electron emission areas EA are normally arranged in a two-dimensional matrix within the effective area of the cathode panel CP (area that functions as an actual display portion). The first opening 14A provided in the second insulating layer 16 and the focusing electrode 17 is disposed so as to surround the electron emission region EA.

  On the other hand, the anode panel AP has a phosphor layer 22 (specifically, a red light-emitting phosphor layer 22R, a green light-emitting phosphor layer 22G, and a blue light-emitting phosphor layer 22B) having a predetermined pattern on the substrate 20. The phosphor layer 22 is formed and covered with the anode electrode 24. The phosphor layers 22 are embedded with a light absorbing layer (black matrix) 23 made of a light absorbing material such as carbon to prevent display image color turbidity and optical crosstalk. is doing. In the figure, reference numeral 21 represents a partition wall, reference numeral 40 represents a spacer, reference numeral 41 represents an antistatic film formed on the surface of the spacer 40, reference numeral 25 represents a spacer holding portion, reference numeral 26 Represents a frame. In FIG. 2, illustration of the partition walls, the spacers, and the spacer holding portions is omitted.

  The anode electrode 24 functions as a reflection film that reflects the light emitted from the phosphor layer 22, and rebounds from the phosphor layer 22 or secondary electrons emitted from the phosphor layer 22 (hereinafter referred to as these The electrons are collectively referred to as backscattered electrons) and have a function of preventing the phosphor layer 22 from being charged. The barrier rib 21 has a function of preventing so-called optical crosstalk (color turbidity) from occurring due to backscattered electrons colliding with another phosphor layer 22.

  One subpixel is composed of an electron emission area EA on the cathode panel side and a phosphor layer 22 on the anode panel side facing a group of these field emission elements. In the effective area, such pixels are arranged on the order of hundreds of thousands to millions, for example. In a display device for color display, one pixel (one pixel) is composed of a set of a red light emitting subpixel, a green light emitting subpixel, and a blue light emitting subpixel.

Then, the anode panel AP and the cathode panel CP are arranged so that the electron emission region EA and the phosphor layer 22 face each other, and are joined to each other through the frame body 26 at the peripheral portion, and then attached to the cathode panel CP. A space sandwiched between the cathode panel CP and the anode panel AP (more specifically, a space surrounded by the cathode panel CP, the anode panel AP, and the frame body 26) is exhausted through a tip tube (not shown). Then, the display device can be manufactured by sealing the chip tube. A space surrounded by the anode panel AP, the cathode panel CP, and the frame body 26 is in a high vacuum (for example, 1 × 10 ⁻³ Pa or less).

Therefore, if the spacer 40 is not disposed between the anode panel AP and the cathode panel CP, the display device is damaged by the atmospheric pressure. An antistatic film 41 made of a transition metal oxide such as CrO _x or CrAl _x O _y is usually formed on the surface of the conventional spacer 40 (see, for example, JP-T-2004-500688).

  12 and 13 schematically show the trajectories of electrons or electron beams in one subpixel located in the vicinity of the spacer 40. FIG. In FIG. 12 and FIG. 13, the anode electrode and the light absorption layer (black matrix) are not shown. Further, the gate electrode 13 extends in a direction perpendicular to the drawing sheet (Y direction in FIGS. 12 and 13), and the cathode electrode 11 extends in a direction parallel to the drawing sheet (X direction in FIGS. 12 and 13).

  As shown in FIG. 12, some of the electrons that have passed through an anode electrode (not shown) in the anode panel AP and collided with the phosphor layer 22 are back-scattered by the phosphor layer 22 as shown in FIG. Some of the backscattered electrons collide with the spacer 40.

JP-T-2004-500688

  By the way, the problems described below are caused by such backscattered electrons. That is, as shown in FIG. 13, some of the backscattered electrons collide with the spacer 40 in the vicinity of the spacer 40. As a result, when the display device is operated (driven) for a long time, the backscattered electrons colliding with the spacer 40 reduce the antistatic film 41 made of a transition metal oxide, and the electric resistance value of the antistatic film 41 is reduced. Causes the problem of fluctuating. When the electric resistance value of the antistatic film 41 fluctuates, the electric field is disturbed in the vicinity of the spacer 40. As a result, the trajectory of the electron beam in one subpixel located in the vicinity of the spacer 40 fluctuates and changes, and the opposing phosphor The electron beam arrival position in the layer 22 changes, and the image quality of the display device deteriorates. Further, the region of the antistatic film 41 in which the resistance is reduced (indicated by the low resistance region in FIG. 13) expands as the display operation (drive) time of the display device increases, and in the worst case, the insulation of the spacer 40 Until it causes destruction.

  Accordingly, an object of the present invention is to display the characteristics of the antistatic film formed on the surface of the spacer disposed in the cold cathode field emission display device so as to display and drive the cold cathode field emission display device over a long period of time. It is to provide a method (in other words, a correction method) that can be maintained and held by the above.

In order to achieve the above object, a method for maintaining the characteristics of an antistatic film formed on the surface of a spacer disposed in a cold cathode field emission display device of the present invention (hereinafter sometimes simply referred to as the present invention) Is
A cathode panel provided with a plurality of cold cathode field emission devices and an anode panel provided with a phosphor layer and an anode electrode are joined at the periphery thereof,
The space between the cathode panel and the anode panel is in a vacuum state,
Between the cathode panel and the anode panel, a plurality of spacers having an antistatic film formed on the surface are disposed,
Cold cathode field emission device
(A) a cathode electrode formed on a support;
(B) a first insulating layer formed on the support and the cathode electrode;
(C) a gate electrode formed on the first insulating layer;
(D) a second insulating layer formed on the gate electrode and the first insulating layer;
(E) a focusing electrode formed on the second insulating layer;
(F) a first opening formed in the focusing electrode and the second insulating layer; a second opening formed in the gate electrode and communicating with the first opening; and a second opening formed in the first insulating layer. A third opening communicating with the part, and
(G) an electron emission portion formed on the cathode electrode exposed at the bottom of the third opening,
A method for maintaining the characteristics of an antistatic film in a cold cathode field emission display comprising:
In a state where no voltage is applied to the anode electrode, a voltage V _G higher than the voltage V _C applied to the cathode electrode is applied to the gate electrode, and a voltage V _F higher than the voltage V _G applied to the gate electrode is applied to the convergence electrode. Then, the electrons emitted from the electron emission portion collide with the focusing electrode, and the gas released from the focusing electrode is adsorbed on the antistatic film.

Here, the focusing electrode is used to converge the trajectory of emitted electrons that are emitted from the second opening and travel toward the anode electrode, thereby making it possible to improve luminance and prevent optical crosstalk between adjacent pixels. Electrode. In a so-called high-voltage type cold cathode field emission display device in which the potential difference between the anode electrode and the cathode electrode is on the order of several kilovolts and the distance between the anode electrode and the cathode electrode is relatively long, the focusing electrode Is particularly effective. During the display operation of the cold cathode field emission display device, a voltage V _F (for example, 0 V) lower than the voltage V _G applied to the gate electrode is applied to the focusing electrode from the focusing electrode control circuit.

  The focusing electrode (more specifically, the first opening) is individually formed so as to surround the electron emission portion or the electron emission region provided in the electron emission region which is an overlapping region where the cathode electrode and the gate electrode overlap. For example, the electron emission part or the electron emission region may be extended along a predetermined arrangement direction, or all of the electron emission part or the electron emission region may be formed by one focusing electrode. It is also possible to have a configuration that surrounds (that is, the focusing electrode may be a thin sheet-like structure covering the entire effective area, which is the central display area that performs a practical function as a cold cathode field emission display) Well, this can have a common convergence effect on multiple electron emitters or electron emission regions.

In the present invention, the focusing electrode is preferably composed of an aluminum (Al) thin film formed by a vacuum deposition method because the focusing electrode is relatively porous and easily adsorbs gas. . However, it is not limited to such a configuration, and other constituent materials for the focusing electrode include chromium (Cr), tungsten (W), niobium (Nb), tantalum (Ta), molybdenum (Mo), copper ( Transitions such as Cu), gold (Au), silver (Ag), titanium (Ti), nickel (Ni), cobalt (Co), zirconium (Zr), iron (Fe), platinum (Pt), zinc (Zn) Various metals including metals; alloys (such as MoW) or compounds including these metal elements (such as nitrides such as TiN, silicides such as WSi ₂ , MoSi ₂ , TiSi ₂ , TaSi ₂ ); silicon (Si), etc. Examples of semiconductors: Carbon thin films such as diamond; conductive metal oxides such as ITO (indium oxide-tin), indium oxide, and zinc oxide; For example, a deposition method such as an electron beam deposition method or a hot filament deposition method, a sputtering method, a chemical vapor deposition method (CVD method), a combination of an ion plating method and an etching method; a screen printing method; a plating method ( Electroplating method or electroless plating method); lift-off method; laser ablation method; sol-gel method.

  In the present invention including the above-described preferred configuration, the antistatic film is preferably made of a metal oxide, and more preferably made of a chromium oxide.

However, the material constituting the antistatic film is not limited to these, and other metal such as graphite, oxide, boride, carbide, sulfide, and nitride can be used. For example, compounds containing a metalloid element ₂ such as a semi-metal and MoSe such as _{graphite, Nd 2 O 3, La x} Ba 2-x CuO 4, La x Ba 2-x CuO 4, La x Y 1-x CrO 3 Oxides such as AlB ₂ and TiB ₂ , carbides such as SiC, sulfides such as MoS ₂ and WS ₂ , and nitrides such as BN, TiN, and AlN. The antistatic film may be composed of a single type of material, may be composed of a plurality of types of materials, may be a single layer structure, or may be a multilayer structure. May be. The antistatic film can be formed based on a known method such as a sputtering method, a vacuum deposition method, a CVD method, or the like. The material constituting the antistatic film preferably has a secondary electron emission coefficient close to 1.

  Since the space between the cathode panel and the anode panel is in a vacuum state, if a spacer is not provided between the anode panel and the cathode panel, the cold cathode field emission display device can be operated by atmospheric pressure. It will be damaged.

  The spacer can be made of ceramics or glass, for example. When the spacer is made of ceramics, the ceramics include mullite, alumina, barium titanate, lead zirconate titanate, zirconia, cordiolite, borosilicate barium, iron silicate, glass ceramic materials, titanium oxide and chromium oxide. Examples thereof include iron oxide, vanadium oxide, and nickel oxide added. In this case, the spacer can be manufactured by forming a so-called green sheet, firing the green sheet, and cutting the green sheet fired product. Moreover, soda-lime glass can be mentioned as glass which comprises a spacer. The spacer may be fixed by being sandwiched between the partition walls, for example. Alternatively, for example, a spacer holding part may be formed on the anode panel and fixed by the spacer holding part.

  Specifically, maintaining (holding) the characteristics of the antistatic film in the present invention means that the electric resistance value of the antistatic film varies or changes even if the electric resistance value of the antistatic film fluctuates or changes. This means returning (correcting) as much as possible to the state before it occurred.

The voltage V _C applied to the cathode electrode, the voltage V _G applied to the gate electrode, and the convergence electrode in a state where no voltage is applied to the anode electrode, that is, in a state where display operation (actual operation) is not performed. An example of the relationship of the voltage V _F is illustrated in Table 1 below.

[Table 1]
Voltage applied to cathode electrode V _C = 0 volts Voltage applied to gate electrode V _G = 30 to 35 volts Voltage applied to focusing electrode V _F = 40 to 100 volts V _G −V _C = 30 to 35 volts V _F − V _G = 10 to 70 volts

  The method of maintaining the characteristics of the antistatic film formed on the surface of the spacer disposed in the cold cathode field emission display device of the present invention is performed when the cold cathode field emission display device performs a display operation (actual operation). More specifically, for example, immediately after the power-off operation of the cold cathode field emission display device and before the power is turned off, for example, according to a predetermined schedule, Good.

  The type of the cold cathode field emission device (hereinafter sometimes abbreviated as field emission device) is not particularly limited, and the Spindt type field emission device (conical electron emission portion is located at the bottom of the third opening). A field emission device provided on the cathode electrode) or a flat type field emission device (a field emission device in which a substantially planar electron emission portion is provided on the cathode electrode located at the bottom of the third opening). Can be mentioned.

  The cathode cathode projected image and the gate electrode projected image are orthogonal to each other, that is, the first direction in which the cathode electrode extends and the second direction in which the gate electrode extends are orthogonal to each other. This is preferable from the viewpoint of simplifying the structure of the apparatus. In the cathode panel, an overlapping region where the cathode electrode and the gate electrode overlap corresponds to an electron emission region, and the electron emission regions are arranged in a two-dimensional matrix, and each electron emission region includes one or more A field emission device is provided.

A field emission device can be generally manufactured by the following method. However, the process of forming the focusing electrode is excluded.
(1) forming a cathode electrode on a support;
(2) forming a first insulating layer on the entire surface (on the support and the cathode electrode);
(3) forming a gate electrode on the first insulating layer;
(4) forming a second opening and a third opening in a portion of the gate electrode and the first insulating layer in the overlapping region of the cathode electrode and the gate electrode, and exposing the cathode electrode to the bottom of the third opening;
(5) A step of forming an electron emission portion on the cathode electrode located at the bottom of the third opening.

Alternatively, the field emission device can be manufactured by the following method. However, the process of forming the focusing electrode is excluded.
(1) forming a cathode electrode on a support;
(2) forming an electron emission portion on the cathode electrode;
(3) forming a first insulating layer on the entire surface (on the support and the electron emission portion or on the support, the cathode electrode and the electron emission portion);
(4) forming a gate electrode on the first insulating layer;
(5) forming a second opening and a third opening in a portion of the gate electrode and the first insulating layer in a region where the cathode electrode and the gate electrode overlap, and exposing an electron emission portion at the bottom of the third opening .

As constituent materials of the cathode electrode and the gate electrode, chromium (Cr), aluminum (Al), tungsten (W), niobium (Nb), tantalum (Ta), molybdenum (Mo), copper (Cu), gold (Au), Various metals including transition metals such as silver (Ag), titanium (Ti), nickel (Ni), cobalt (Co), zirconium (Zr), iron (Fe), platinum (Pt), zinc (Zn); Alloys (eg, MoW) or compounds (eg, nitrides such as TiN, silicides such as WSi ₂ , MoSi ₂ , TiSi ₂ , TaSi ₂ ); semiconductors such as silicon (Si); carbon thin films such as diamond And conductive metal oxides such as ITO (indium oxide-tin), indium oxide, and zinc oxide. In addition, as a method for forming these electrodes, for example, a vapor deposition method such as an electron beam vapor deposition method or a hot filament vapor deposition method, a sputtering method, a combination of a CVD method, an ion plating method and an etching method; a screen printing method; Plating method and electroless plating method); lift-off method; laser ablation method; sol-gel method and the like. According to the screen printing method or the plating method, for example, a strip-like cathode electrode or gate electrode can be formed directly.

  In the Spindt-type field emission device, as the material constituting the electron emission portion, molybdenum, molybdenum alloy, tungsten, tungsten alloy, titanium, titanium alloy, niobium, niobium alloy, tantalum, tantalum alloy, chromium, chromium alloy, and And at least one material selected from the group consisting of silicon (polysilicon and amorphous silicon) containing impurities. The electron emission portion of the Spindt-type field emission device can be formed by, for example, a sputtering method or a CVD method in addition to the vacuum evaporation method.

In the flat field emission device, it is preferable that the material constituting the electron emission portion is composed of a material having a work function Φ smaller than that of the material constituting the cathode electrode. What is necessary is just to determine based on the work function of the material which comprises a cathode electrode, the electric potential difference between a gate electrode and a cathode electrode, the magnitude | size of the emission electron current density requested | required, etc. As typical materials constituting the cathode electrode in the field emission device, tungsten (Φ = 4.55 eV), niobium (Φ = 4.02 to 4.87 eV), molybdenum (Φ = 4.53 to 4.95 eV), Examples include aluminum (Φ = 4.28 eV), copper (Φ = 4.6 eV), tantalum (Φ = 4.3 eV), and chromium (Φ = 4.5 eV). The electron emission portion preferably has a work function Φ smaller than these materials, and the value is preferably approximately 3 eV or less. As such materials, carbon (Φ <1 eV), cesium (Φ = 2.14 eV), LaB ₆ (Φ = 2.66-2.76 eV), BaO (Φ = 1.6-2.7 eV), SrO (Φ = 1.25 to 1.6 eV), Y ₂ O ₃ (Φ = 2.0 eV), CaO (Φ = 1.6 to 1.86 eV), BaS (Φ = 2.05 eV), TiN (Φ = 2. 92 eV) and ZrN (Φ = 2.92 eV). More preferably, the electron emission portion is made of a material having a work function Φ of 2 eV or less. In addition, the material which comprises an electron emission part does not necessarily need to be provided with electroconductivity.

Alternatively, in the flat type field emission device, as a material constituting the electron emission portion, a material in which the secondary electron gain δ of the material is larger than the secondary electron gain δ of the conductive material constituting the cathode electrode is used. You may select suitably. That is, silver (Ag), aluminum (Al), gold (Au), cobalt (Co), copper (Cu), molybdenum (Mo), niobium (Nb), nickel (Ni), platinum (Pt), tantalum (Ta) ), Metals such as tungsten (W), zirconium (Zr); semiconductors such as germanium (Ge); inorganic simple substances such as carbon and diamond; and aluminum oxide (Al ₂ O ₃ ), barium oxide (BaO), beryllium oxide ( BeO), calcium oxide (CaO), magnesium oxide (MgO), tin oxide (SnO ₂ ), barium fluoride (BaF ₂ ), calcium fluoride (CaF ₂ ) and other compounds can be selected as appropriate. . In addition, the material which comprises an electron emission part does not necessarily need to be provided with electroconductivity.

Alternatively, in the flat type field emission device, carbon, more specifically, amorphous diamond, graphite, carbon nanotube structure, ZnO whisker, MgO whisker, SnO ₂ whisker is particularly preferable as a constituent material of the electron emission part. , MnO whiskers, Y ₂ O ₃ whiskers, NiO whiskers, ITO whiskers, In ₂ O ₃ whiskers, and Al ₂ O ₃ whiskers. When the electron emission portion is composed of these, the emission electron current density required for the cold cathode field emission display device can be obtained with an electric field intensity of 5 × 10 ⁶ V / m or less. Further, if the material constituting the electron emission portion is an electric resistor, the emission electron current obtained from each electron emission portion can be made uniform, and accordingly, when incorporated in a cold cathode field emission display device. Luminance variation can be suppressed. Furthermore, since these materials have extremely high resistance to the sputtering effect by ions of residual gas in the cold cathode field emission display, the lifetime of the field emission device can be extended.

  Specific examples of the carbon nanotube structure include carbon nanotubes and / or graphite nanofibers. More specifically, the electron emission part may be composed of carbon nanotubes, the electron emission part may be composed of graphite nanofibers, or the electron emission is performed from a mixture of carbon nanotubes and graphite nanofibers. You may comprise a part. Macroscopically, carbon nanotubes and graphite nanofibers may be in the form of powder or thin film. In some cases, the carbon nanotube structure has a conical shape. It may be. Carbon nanotubes and graphite nanofibers are well-known physical vapor deposition methods (PVD methods) such as arc discharge method and laser ablation method, plasma CVD method, laser CVD method, thermal CVD method, gas phase synthesis method, gas phase It can be manufactured and formed by various CVD methods such as a growth method.

As the constituent material of the first insulating layer and the second insulating _{layer, SiO 2, BPSG, PSG,} BSG, AsSG, PbSG, SiON, SOG ( spin on glass), low-melting glass, SiO ₂ based materials such glass paste; SiN-based material An insulating resin such as polyimide can be used alone or in appropriate combination. A known process such as a CVD method, a coating method, a sputtering method, or a screen printing method can be used to form the first insulating layer and the second insulating layer.

  When the opening is cut along a virtual plane parallel to the surface of the support (second opening (opening formed in the gate electrode)) or third opening (opening formed in the first insulating layer) Can be any shape such as a circle, an ellipse, a rectangle, a polygon, a rounded rectangle, or a rounded polygon. In addition, the planar shape of the first opening (the opening formed in the second insulating layer) can be any shape such as a rectangle, a rounded rectangle, a circle, an ellipse, a polygon, a rounded polygon, and the like. It can be. The formation of the second opening can be performed by, for example, anisotropic etching, isotropic etching, a combination of anisotropic etching and isotropic etching, or, depending on the method of forming the gate electrode, The second opening can also be formed directly. The formation of the third opening or the first opening can also be performed by, for example, anisotropic etching, isotropic etching, or a combination of anisotropic etching and isotropic etching.

  In the field emission device, depending on the structure of the field emission device, one electron emission portion may exist in one third opening, or a plurality of electron emission portions exist in one third opening. Alternatively, a plurality of second openings may be provided in the gate electrode, one third opening communicating with the second opening may be provided in the first insulating layer, and one of the first openings provided in the first insulating layer may be provided. One or a plurality of electron emission portions may be present in the third opening.

In the field emission device, a resistor thin film may be formed between the cathode electrode and the electron emission portion. By forming the resistor thin film, it is possible to stabilize the operation of the field emission device and make the electron emission characteristics uniform. As a material constituting the resistor thin film, a carbon-based resistor material such as silicon carbide (SiC) or SiCN, a semiconductor resistor material such as SiN or amorphous silicon, a high melting point such as ruthenium oxide (RuO ₂ ), tantalum oxide, or tantalum nitride. A metal oxide can be illustrated. Examples of the method for forming the resistor thin film include a sputtering method, a CVD method, and a screen printing method. The electrical resistance value per one electron emitting portion may be approximately 1 × 10 ⁶ to 1 × 10 ¹¹ Ω, preferably several tens of gigaΩ.

  In the cold cathode field emission display, a strong electric field generated by a voltage applied to the cathode electrode and the gate electrode is applied to the electron emission portion, and as a result, electrons are emitted from the electron emission portion by the quantum tunnel effect. The electrons are attracted to the anode panel by the anode electrode provided on the anode panel, and collide with the phosphor layer. As a result of the collision of electrons with the phosphor layer, the phosphor layer emits light and can be recognized as an image.

In the cold cathode field emission display, the cathode electrode is connected to the cathode electrode control circuit, the gate electrode is connected to the gate electrode control circuit, the focusing electrode is connected to the focusing electrode control circuit, and the anode electrode is connected to the anode electrode control circuit. It is connected. Note that these control circuits can be constituted by known circuits. During the display operation (actual operation), the anode voltage _{VA that} is the output voltage of the anode electrode control circuit and is applied to the anode electrode is usually constant, and can be set to, for example, 5 kilovolts to 15 kilovolts. Alternatively, the value of V _A / d (unit: kilovolt / mm, d is the distance between the support and the substrate and satisfies 0.5 mm ≦ d ≦ 10 mm) is 0.5 or more and 20 Hereinafter, it is desirable to satisfy 1 or more and 10 or less, and more preferably 5 or more and 10 or less.

In the actual operation of the cold cathode field emission display device, regarding the voltage V _C applied to the cathode electrode and the voltage V _G applied to the gate electrode, when the voltage modulation method is adopted as the gradation control method,
(1) A method of changing the voltage V _G applied to the gate electrode while keeping the voltage V _C applied to the cathode electrode constant (2) A voltage V _G applied to the gate electrode by changing the voltage V _C applied to the cathode electrode (3) There is a method in which the voltage V _C applied to the cathode electrode is changed and the voltage V _G applied to the gate electrode is also changed.

As a substrate constituting an anode panel or as a support constituting a cathode panel, a glass substrate, a glass substrate with an insulating film formed on the surface, a quartz substrate, a quartz substrate with an insulating film formed on the surface, and a surface Examples of the semiconductor substrate include an insulating film. From the viewpoint of reducing manufacturing costs, it is preferable to use a glass substrate or a glass substrate having an insulating film formed on the surface. As a glass substrate, high strain point glass, soda glass (Na ₂ O · CaO · SiO ₂ ), borosilicate glass (Na ₂ O · B ₂ O ₃ · SiO ₂ ), forsterite (2MgO · SiO ₂ ), lead glass (Na ₂ O · PbO · SiO ₂ ) can be exemplified.

As a configuration example of the anode electrode and the phosphor layer in the anode panel,
(1) A configuration in which an anode electrode is formed on a substrate and a phosphor layer is formed on the anode electrode,
(2) A configuration in which a phosphor layer is formed on a substrate and an anode electrode is formed on the phosphor layer;
Can be mentioned. In the configuration (1), a so-called metal back film that is electrically connected to the anode electrode may be formed on the phosphor layer. In the configuration (2), a metal back film may be formed on the anode electrode.

The anode electrode may be composed of one anode electrode as a whole, or may be composed of a plurality of anode electrode units. In the latter case, the anode electrode unit and the anode electrode unit need to be electrically connected by a resistor layer. As the material constituting the resistor layer, carbon-based resistor materials such as silicon carbide (SiC) and SiCN; SiN-based materials; refractory metals such as ruthenium oxide (RuO ₂ ), tantalum oxide, tantalum nitride, chromium oxide, and titanium oxide An oxide; a semiconductor resistor material such as amorphous silicon can be used. Examples of the sheet resistance value of the resistor layer include 1 × 10 ⁻¹ Ω / □ to 1 × 10 ¹⁰ Ω / □, preferably 1 × 10 ³ Ω / □ to 1 × 10 ⁸ Ω / □. The number (Q) of anode electrode units may be two or more. For example, when the total number of rows of phosphor layers arranged in a straight line is q, Q = q or q = k · Q (K is an integer of 2 or more, preferably 10 ≦ k ≦ 100, more preferably 20 ≦ k ≦ 50), or a number obtained by adding 1 to the number of spacers arranged at a constant interval. It can also be a number that matches the number of pixels or sub-pixels, or an integer fraction of the number of pixels or sub-pixels. The size of each anode electrode unit may be the same regardless of the position of the anode electrode unit, or may vary depending on the position of the anode electrode unit. Note that, even when the anode electrode is composed of one anode electrode as a whole or when the anode electrode is composed of a plurality of anode electrode units, a resistor layer is formed on the surface of the entire anode electrode. May be formed.

As an anode electrode forming method, for example, various PVD methods such as an evaporation method such as an electron beam evaporation method and a hot filament evaporation method, a sputtering method, an ion plating method and a laser ablation method; various CVD methods; a screen printing method; a metal mask Examples thereof include printing methods; lift-off methods; sol-gel methods. That is, it is possible to form an anode electrode by forming a conductive material layer made of a conductive material and patterning the conductive material layer based on a lithography technique and an etching technique. Alternatively, the anode electrode can be obtained by forming a conductive material based on a PVD method or a screen printing method through a mask or screen having an anode electrode pattern. The resistor layer can also be formed by a similar method. That is, a resistor layer may be formed from a resistor material, and the resistor layer may be patterned based on a lithography technique and an etching technique, or the resistor material may be provided via a mask or screen having a resistor layer pattern. The resistor layer can be obtained by formation based on the PVD method or the screen printing method. The average thickness of the anode electrode on the substrate (or above the substrate) is 5 × 10 ⁻⁸ m (50 nm) to 5 × 10 ⁻⁷ m (0.5 μm), preferably 8 × 10 ⁻⁸ m (80 nm) to An example is 3 × 10 ⁻⁷ m (0.3 μm).

The constituent material of the anode electrode may be appropriately selected according to the configuration of the cold cathode field emission display. That is, when the cold cathode field emission display is a transmission type (the anode panel corresponds to the display surface), and the anode electrode and the phosphor layer are laminated in this order on the substrate, the substrate is Originally, the anode electrode itself needs to be transparent, and a transparent conductive material such as ITO (indium tin oxide) is used. On the other hand, when the cold cathode field emission display is of a reflective type (the cathode panel corresponds to the display surface), and even if it is a transmissive type, the phosphor layer and the anode electrode are laminated in this order on the substrate. In the case of molybdenum (Mo), aluminum (Al), chromium (Cr), tungsten (W), niobium (Nb), tantalum (Ta), gold (Au), silver (Ag), titanium (Ti), Metals such as cobalt (Co), zirconium (Zr), iron (Fe), platinum (Pt), zinc (Zn); alloys or compounds containing these metal elements (for example, nitrides such as TiN, WSi ₂ , MoSi _2, TiSi _2, silicides such as TaSi _2); thin carbon film such as diamond; silicon (Si) semiconductor such as ITO (indium - tin), indium oxide, conductive metal such as zinc oxide It can be exemplified oxides. When the resistor layer is formed, the anode electrode is preferably made of a conductive material that does not change the resistance value of the resistor layer. For example, when the resistor layer is made of silicon carbide (SiC), the anode electrode is It is preferable to comprise from molybdenum (Mo).

  The phosphor layer may be composed of single-color phosphor particles or may be composed of three primary color phosphor particles. The phosphor layer is arranged in a dot pattern. Specifically, when the cold cathode field emission display device performs color display, examples of the arrangement and arrangement of the phosphor layers include a delta arrangement, a stripe arrangement, a diagonal arrangement, and a rectangle arrangement. That is, one row of the phosphor layers arranged in a straight line includes a row in which all of the red light emitting unit phosphor layers are occupied, a row in which the green light emitting unit phosphor layer is occupied, and a blue light emitting unit phosphor layer. Or may be composed of a column in which a red light emitting unit phosphor layer, a green light emitting unit phosphor layer, and a blue light emitting unit phosphor layer are sequentially arranged. Here, the unit phosphor layer is defined as a phosphor layer (phosphor region) that generates one bright spot on the anode panel. One pixel (one pixel) is composed of a set of one red light emitting unit phosphor layer, one green light emitting unit phosphor layer, and one blue light emitting unit phosphor layer. It is composed of one unit phosphor layer (one red light emitting unit phosphor layer, one green light emitting unit phosphor layer, or one blue light emitting unit phosphor layer).

  The phosphor layer uses a luminescent crystal particle composition prepared from luminescent crystal particles (for example, phosphor particles having a particle size of about 5 to 10 nm), for example, a red photosensitive luminescent crystal particle composition. (Red phosphor slurry) is applied to the entire surface, exposed and developed to form a red light emitting phosphor layer, and then a green photosensitive luminescent crystal particle composition (green phosphor slurry) is applied to the entire surface. Then, it is exposed to light and developed to form a green light emitting phosphor layer. Further, a blue photosensitive luminescent crystal particle composition (blue phosphor slurry) is applied to the entire surface, exposed to light and developed to emit blue light. It can be formed by a method of forming a phosphor layer. Alternatively, after sequentially applying the red light emitting phosphor slurry, the green light emitting phosphor slurry, and the blue light emitting phosphor slurry, each phosphor slurry may be sequentially exposed and developed to form each phosphor layer. Each phosphor layer may be formed by a screen printing method, an inkjet method, a float coating method, a sedimentation coating method, a phosphor film transfer method, or the like. The average thickness of the phosphor layer on the substrate is not limited, but is preferably 3 μm to 20 μm, preferably 5 μm to 10 μm.

The phosphor material constituting the luminescent crystal particles can be appropriately selected from conventionally known phosphor materials. In the case of color display, a phosphor material whose color purity is close to the three primary colors specified by NTSC, white balance is achieved when the three primary colors are mixed, the afterglow time is short, and the afterglow time of the three primary colors is almost equal. It is preferable to combine them. As phosphor materials constituting the red light emitting phosphor layer, (Y ₂ O ₃ : Eu), (Y ₂ O ₂ S: Eu), (Y ₃ Al ₅ O ₁₂ : Eu), (Y ₂ SiO ₅ : Eu) ) And (Zn ₃ (PO ₄ ) ₂ : Mn) can be exemplified, among which (Y ₂ O ₃ : Eu) and (Y ₂ O ₂ S: Eu) are preferably used. Further, as the phosphor material constituting the green light emitting phosphor layer, (ZnSiO ₂ : Mn), (Sr ₄ Si ₃ O ₈ Cl ₄ : Eu), (ZnS: Cu, Al), (ZnS: Cu, Au, Al), [(Zn, Cd) S: Cu, Al], (Y ₃ Al ₅ O ₁₂ : Tb), (Y ₂ SiO ₅ : Tb), [Y ₃ (Al, Ga) ₅ O ₁₂ : Tb] , (ZnBaO ₄ : Mn), (GbBO ₃ : Tb), (Sr ₆ SiO ₃ Cl ₃ : Eu), (BaMgAl ₁₄ O ₂₃ : Mn), (ScBO ₃ : Tb), (Zn ₂ SiO ₄ : Mn) , (ZnO: Zn), (Gd ₂ O ₂ S: Tb), and (ZnGa ₂ O ₄ : Mn), (ZnS: Cu, Al), (ZnS: Cu, Au, Al), [(Zn, Cd ) S: Cu, Al], (Y 3 Al 5 O 12: Tb), [Y 3 (A _{, Ga) 5 O 12: Tb} ], (Y 2 SiO 5: Tb) is preferably used. Further, as phosphor materials constituting the blue light emitting phosphor layer, (Y ₂ SiO ₅ : Ce), (CaWO ₄ : Pb), CaWO ₄ , YP _0.85 V _0.15 O ₄ , (BaMgAl ₁₄ O ₂₃ : Eu) , (Sr ₂ P ₂ O ₇ : Eu), (Sr ₂ P ₂ O ₇ : Sn), (ZnS: Ag, Al), (ZnS: Ag), ZnMgO, and ZnGaO _4. , (ZnS: Ag), (ZnS: Ag, Al) are preferably used.

  In the present invention, it is possible to prevent so-called optical crosstalk (color turbidity) from occurring when electrons recoiled from the phosphor layer or secondary electrons emitted from the phosphor layer enter another phosphor layer. In addition, when the electrons recoiled from the phosphor layer or the secondary electrons emitted from the phosphor layer enter the other phosphor layer beyond the barrier, In order to prevent collision with the phosphor layer, it is desirable that a partition wall be provided.

  Examples of the method for forming the lattice-shaped partition walls include a screen printing method, a dry film method, a photosensitive method, a casting method, and a sandblast forming method. Here, in the screen printing method, an opening is formed in a portion of the screen corresponding to a portion where a partition is to be formed, and the partition forming material on the screen is passed through the opening using a squeegee, and the partition is formed on the substrate. In this method, after the formation material layer is formed, the partition wall formation material layer is fired. The dry film method is a method of laminating a photosensitive film on a substrate, removing the photosensitive film at the part where the partition wall is to be formed by exposure and development, embedding the partition wall forming material in the opening generated by the removal, and baking. . The photosensitive film is burned and removed by baking, and the partition wall-forming material embedded in the openings remains to form partition walls. The photosensitive method is a method in which a barrier rib-forming material layer having photosensitivity is formed on a substrate, the barrier rib-forming material layer is patterned by exposure and development, and then fired (cured). The casting method (embossing molding method) refers to a method for forming a partition wall forming material layer by extruding a partition wall forming material layer made of a paste-like organic material or inorganic material onto a substrate from a mold (cast). In this method, the partition wall forming material layer is fired. The sand blast forming method is, for example, forming a partition wall forming material layer on a substrate using a screen printing or metal mask printing method, a roll coater, a doctor blade, a nozzle discharge type coater, etc. In this method, the part of the partition wall forming material layer to be covered is covered with a mask layer, and then the exposed part of the partition wall forming material layer is removed by sandblasting. After the partition wall is formed, the partition wall may be polished to flatten the top surface of the partition wall.

Examples of the partition wall forming material include photosensitive polyimide resin, lead glass colored with a metal oxide such as cobalt oxide, SiO ₂ , and a low melting point glass paste. On the surface (top surface and side surface) of the partition wall, a layer (for example, made of SiN) for preventing an electron beam from colliding with the partition wall and releasing gas from the partition wall may be formed.

  As a planar shape of the part surrounding the phosphor layer in the lattice-shaped partition wall (corresponding to the inner contour line of the projected image of the partition wall side surface and a kind of opening region), a rectangular shape, a circular shape, an elliptical shape, an oval shape, Examples include a triangular shape, a pentagonal or higher polygonal shape, a rounded triangular shape, a rounded rectangular shape, and a rounded polygon. By arranging these planar shapes (planar shapes of the opening regions) in a two-dimensional matrix, a grid-like partition is formed. This two-dimensional matrix-like arrangement may be arranged, for example, like a cross or like a zigzag.

  The light absorption layer that absorbs light from the phosphor layer is preferably formed between adjacent phosphor layers or between the partition wall and the substrate from the viewpoint of improving the contrast of the display image. Here, the light absorption layer functions as a so-called black matrix. As a material constituting the light absorption layer, it is preferable to select a material that absorbs 99% or more of light from the phosphor layer. Such materials include carbon, metal thin films (eg, chromium, nickel, aluminum, molybdenum, etc., or alloys thereof), metal oxides (eg, chromium oxide), metal nitrides (eg, chromium nitride), heat resistance Materials such as photosensitive organic resins, glass pastes, glass pastes containing conductive particles such as black pigments and silver, and specifically, photosensitive polyimide resins, chromium oxides, and chromium oxide / chromium laminated films Can be illustrated. In the chromium oxide / chromium laminated film, the chromium film is in contact with the substrate. For example, the light absorption layer is a combination of a vacuum vapor deposition method, a sputtering method and an etching method, a vacuum vapor deposition method, a sputtering method, a combination of a spin coating method and a lift-off method, a screen printing method, a lithography technique, etc. It can be formed by a method appropriately selected depending on the method.

The cathode panel and the anode panel are joined at the peripheral edge. The joining may be performed using an adhesive layer, or a frame made of an insulating rigid material such as glass or ceramics and an adhesive layer are used in combination. May be. When using a frame and an adhesive layer together, the opposing distance between the cathode panel and the anode panel is set longer than when only the adhesive layer is used by appropriately selecting the height of the frame. Is possible. As a constituent material of the adhesive layer, frit glass is generally used, but a so-called low melting point metal material having a melting point of about 120 to 400 ° C. may be used. Such low melting point metal materials include In (indium: melting point 157 ° C.); indium-gold based low melting point alloy; Sn ₈₀ Ag ₂₀ (melting point 220 to 370 ° C.), Sn ₉₅ Cu ₅ (melting point 227 to 370 ° C.) C) tin (Sn) type high temperature solder such as Pb _97.5 Ag _2.5 (melting point 304 ° C.), Pb _94.5 Ag _5.5 (melting point 304 to 365 ° C.), Pb _97.5 Ag _1.5 Sn _1.0 (melting point 309 ° C.), etc. Lead (Pb) high temperature solder; zinc (Zn) high temperature solder such as Zn ₉₅ Al ₅ (melting point 380 ° C.); Sn ₅ Pb ₉₅ (melting point 300 to 314 ° C.), Sn ₂ Pb ₉₈ (melting point 316 to 322) Tin-lead standard solder such as ° C); brazing material such as Au ₈₈ Ga ₁₂ (melting point 381 ° C) (the above subscripts all represent atomic%).

  When joining the three of the cathode panel, the anode panel and the frame, the three may be joined at the same time, or in the first stage, either the cathode panel or the anode panel and the frame are joined, In the second stage, the other of the cathode panel or the anode panel and the frame may be joined. If the three-party simultaneous bonding or the second stage bonding is performed in a high vacuum atmosphere, the space between the cathode panel and the anode panel becomes a high vacuum simultaneously with the bonding. Alternatively, the space can be evacuated and evacuated after the three members are joined. When exhausting after joining, the pressure of the atmosphere at the time of joining may be normal pressure / depressurized, and the gas constituting the atmosphere may be air, or nitrogen gas or group 0 of the periodic table An inert gas containing a gas belonging to (for example, Ar gas) may be used.

  When exhaust is performed, exhaust can be performed through a tip tube connected in advance to the cathode panel and / or the anode panel. The tip tube is typically configured by using a glass tube, and an ineffective area of the cathode panel and / or the anode panel (a display area in the central portion that performs a practical function as a cold cathode field emission display device) It is joined to the periphery of the through-hole provided in the frame-like region) using frit glass or the above-mentioned low melting point metal material, and after the space has reached a predetermined degree of vacuum, it is sealed by thermal fusion. Cut off. In addition, if the entire cold cathode field emission display is once heated and then cooled before sealing, the residual gas can be released into the space, and the residual gas can be removed out of the space by exhaust. This is preferable.

In the present invention, in a state where no voltage is applied to the anode electrode, a voltage V _G higher than the voltage V _C applied to the cathode electrode is applied to the gate electrode, and a voltage higher than the voltage V _G applied to the gate electrode. by applying a V _F in the focusing electrode, by colliding electrons emitted from the electron emission portion in the focusing electrode, thereby releasing the gas from the focusing electrode. Of the gases released from the focusing electrode [for example, oxygen gas (O ₂ ), hydrogen gas (H ₂ ), methane gas (CH ₄ ), carbon monoxide gas (CO), carbon dioxide gas (CO ₂ )] When the gas having an oxidizing action is adsorbed on the antistatic film, the antistatic film is oxidized again even if the antistatic film is in a reduced state due to collision of some of the backscattered electrons with the spacer. Therefore, the electrical resistance value of the antistatic film can be returned (corrected) to a state before the antistatic film is reduced (or a state close to the state before the antistatic film is reduced). Therefore, there is no disturbance in the electric field in the vicinity of the spacer, the trajectory of the electron beam in one subpixel located in the vicinity of the spacer fluctuates and changes, the electron beam arrival position in the opposing phosphor layer changes, and the cooling is reduced. It is possible to prevent the occurrence of the problem that the image quality of the cathode field emission display is deteriorated.

  Hereinafter, the present invention will be described based on examples with reference to the drawings.

  Example 1 is a method for maintaining the characteristics of an antistatic film formed on the surface of a spacer disposed in a cold cathode field emission display device (hereinafter abbreviated as a display device) of the present invention (hereinafter referred to as antistatic film characteristics). It may be abbreviated as a maintenance method).

As shown in the schematic partial end view of FIG. 1 or FIG. 3, the display device of Example 1 is a cathode provided with a plurality of cold cathode field emission devices (hereinafter abbreviated as field emission devices). The panel CP and the anode panel AP provided with the phosphor layer 22 and the anode electrode 24 are joined at their peripheral portions, and the space between the cathode panel CP and the anode panel AP is in a vacuum state (pressure: for example, 10 ⁻³ Pa or less). Between the cathode panel CP and the anode panel AP, a plurality of spacers 40 having antistatic films 41 formed on the surface are disposed. A schematic exploded perspective view of a part of the cathode panel CP and the anode panel AP when the cathode panel CP and the anode panel AP are disassembled is the same as that shown in FIG.

And the field emission device is
(A) A strip-shaped cathode electrode 11 formed on the support 10 and extending in the first direction;
(B) a first insulating layer 12 formed on the support 10 and the cathode electrode 11;
(C) a gate electrode 13 formed on the first insulating layer 12 and extending in a second direction different from the first direction;
(D) a second insulating layer 16 formed on the gate electrode 13 and the first insulating layer 12,
(E) a focusing electrode 17 formed on the second insulating layer 16;
(F) The first opening 14A formed in the focusing electrode 17 and the second insulating layer 16, the second opening 14B formed in the gate electrode 13 and communicated with the first opening 14A, and the first insulating layer 12 A third opening 14C formed in communication with the second opening 14B, and
(G) Electron emission portions 15, 15A formed on the cathode electrode 11 exposed at the bottom of the third opening 14C;
Consists of.

  Here, in the display device shown in FIG. 1, the electron emission portion 15 has a conical shape, and the electron emission portion 15 constitutes a Spindt-type field emission device. On the other hand, in the display device shown in FIG. 3, a flat field emission device is configured by the electron emission portion 15A. The electron emission portion 15A includes, for example, a large number of carbons partially embedded in a matrix.・ It consists of nanotubes. In the electron emission portions 15 and 15 </ b> A, electron emission is controlled by applying a voltage to the cathode electrode 11 and the gate electrode 13.

  In the cathode panel CP, the cathode electrode 11 has a strip shape extending in the first direction (shown by the X direction in FIG. 1 or FIG. 3), and the gate electrode 13 has a second direction (FIG. 1 or FIG. 1) different from the first direction. This is a strip shape extending in the Y direction in FIG. In general, the cathode electrode 11 and the gate electrode 13 are each formed in a strip shape in a direction in which the projected images of both the electrodes 11 and 13 are orthogonal to each other. An overlapping region where the strip-shaped cathode electrode 11 and the strip-shaped gate electrode 13 overlap is an electron emission region EA, which corresponds to one subpixel. The electron emission areas EA are usually arranged in a two-dimensional matrix within the effective area of the cathode panel CP. One or a plurality of field emission elements are provided in the electron emission area EA corresponding to one subpixel.

  The focusing electrode 17 is formed on the second insulating layer 16 so as to cover the entire surface of the second insulating layer 16, and has a structure that exerts a common focusing effect on the entire field emission device.

  On the other hand, the anode panel AP includes a substrate 20 and a phosphor layer 22 formed on the substrate 20 (in the case of color display, a red light-emitting phosphor layer 22R, a green light-emitting phosphor layer 22G, and a blue light-emitting phosphor layer 22B). ) And an anode electrode 24 covering the phosphor layer 22. That is, the anode panel AP is more specifically formed on the substrate 20 and the substrate 20 between the partition walls 21 formed on the substrate 20 and the phosphor layer 22 made of a large number of phosphor particles. (A red light emitting phosphor layer 22R, a green light emitting phosphor layer 22G, a blue light emitting phosphor layer 22B), and an anode electrode 24 formed on the phosphor layer 22. The anode electrode 24 is in the form of a thin sheet that covers the effective area, and is connected to the anode electrode control circuit 34. The anode electrode 24 is made of aluminum (Al) having a thickness of about 70 nm, and is provided so as to cover the partition wall 21 and the phosphor layer 22. Between the phosphor layer 22 and the phosphor layer 22, and between the partition wall 21 and the substrate 20, a light absorption layer (black) is used to prevent the occurrence of color turbidity and optical crosstalk in the display image. A matrix 23 is formed.

  The anode electrode 24 functions as a reflection film that reflects the light emitted from the phosphor layer 22, and rebounds from the phosphor layer 22 or secondary electrons emitted from the phosphor layer 22 (hereinafter referred to as these The electrons are collectively referred to as backscattered electrons) and have a function of preventing the phosphor layer 22 from being charged. The barrier rib 21 has a function of preventing so-called optical crosstalk (color turbidity) from occurring due to backscattered electrons colliding with another phosphor layer 22.

  An example of the arrangement state of the barrier rib 21, the spacer 40, and the phosphor layer 22 is schematically shown in FIGS. The arrangement of the phosphor layers and the like in the schematic partial end view of the anode panel AP shown in FIG. 1 or FIG. 3 has the configuration shown in FIG. 5 or FIG. Also, the anode electrode is not shown in FIGS. The planar shape of the partition wall 21 is a lattice shape (cross-beam shape), that is, a shape corresponding to one subpixel, for example, a shape surrounding the four sides of the phosphor layer 22 having a substantially rectangular shape (FIGS. 4, 5, 6, and 6). 7), or a belt-like shape extending in parallel with two opposite sides of the substantially rectangular (or belt-like) phosphor layer 22 (see FIGS. 8 and 9). In the phosphor layer 22 shown in FIG. 8, the phosphor layers 22R, 22G, and 22B can be formed in a strip shape extending in the vertical direction in FIG. A part of the partition wall 21 also functions as a spacer holding part 25 for holding the spacer 40.

  One subpixel is composed of an electron emission area EA on the cathode panel side and a phosphor layer 22 on the anode panel side facing a group of these field emission elements. In the effective area, such pixels are arranged on the order of hundreds of thousands to millions, for example. In a display device for color display, one pixel (one pixel) is composed of a set of a red light emitting subpixel, a green light emitting subpixel, and a blue light emitting subpixel.

A spacer 40 made of alumina (Al ₂ O ₃ , purity 99.8 wt%) is disposed between the cathode panel CP and the anode panel AP, and a film is formed on the surface (all of the side surfaces) of the spacer 40. An antistatic film 41 made of a metal oxide having a thickness of 2 nm to 10 nm μm, specifically a chromium oxide, is formed by a sputtering method. The spacer 40 has a length of 100 mm, a height of 3 mm, and a thickness of 50 μm. Contact electrodes (not shown) are provided on the top and bottom surfaces of the spacer 40. The contact electrode provided on the top surface of the spacer 40 is in contact with the anode electrode 24, and the contact electrode provided on the bottom surface of the spacer 40 is in contact with the focusing electrode 17, thereby holding the spacer 40 at a predetermined potential. Can do.

In the display device of Example 1, the cathode electrode 11 is connected to the cathode electrode control circuit 31, the gate electrode 13 is connected to the gate electrode control circuit 32, the focusing electrode 17 is connected to the focusing electrode control circuit 33, and the anode electrode 24. Are connected to the anode electrode control circuit 34. These control circuits can be constituted by known circuits. During actual operation of the display device, the output voltage V _A of the anode electrode control circuit 34 is normally constant, and can be, for example, 5 kilovolts to 15 kilovolts. On the other hand, regarding the voltage V _C applied to the cathode electrode 11 and the voltage V _G applied to the gate electrode 13 during actual operation of the display device,
(1) A method in which the voltage V _C applied to the cathode electrode 11 is constant and the voltage V _G applied to the gate electrode 13 is changed. (2) The voltage V _C applied to the cathode electrode 11 is changed and applied to the gate electrode 13. the voltage V _G for changing the voltage V _C applied to the method (3) a cathode electrode 11, constant, and may employ any method to change the voltage V _G applied to the gate electrode 13.

During actual operation of the display device, a relatively negative voltage is applied to the cathode electrode 11 from the cathode electrode control circuit 31, and a relatively positive voltage is applied to the gate electrode 13 from the gate electrode control circuit 32. A relatively negative voltage (for example, 0 volts) is applied from the focusing electrode control circuit 33, and a positive voltage higher than that of the gate electrode 13 is applied to the anode electrode 24 from the anode electrode control circuit 34. When performing display in such a display device, for example, a scanning signal is input to the cathode electrode 11 from the cathode electrode control circuit 31, and a video signal is input to the gate electrode 13 from the gate electrode control circuit 32. Note that a video signal may be input to the cathode electrode 11 from the cathode electrode control circuit 31, and a scanning signal may be input to the gate electrode 13 from the gate electrode control circuit 32. Electrons are emitted from the electron emission portions 15 and 15A based on the quantum tunnel effect due to an electric field generated when a voltage is applied between the cathode electrode 11 and the gate electrode 13, and the electrons are attracted to the anode electrode 24. It passes through 24 and collides with the phosphor layer 22. As a result, the phosphor layer 22 is excited to emit light, and a desired image can be obtained. That is, the operation of this display device is basically controlled by the voltage V _G applied to the gate electrode 13 and the voltage V _C applied to the cathode electrode 11.

In the antistatic film characteristic maintaining method (antistatic film characteristic correcting method) of Example 1, the voltage is not applied to the anode electrode 24, that is, the display operation (actual operation) is not performed. A voltage V _G higher than the voltage V _C applied to the cathode electrode 11 is applied to the gate electrode 13, and a voltage V _F higher than the voltage V _G applied to the gate electrode 13 is applied to the convergence electrode 17. An example of the relationship between the voltage V _C applied to the cathode electrode 11, the voltage V _G applied to the gate electrode 13, and the voltage V _F applied to the convergence electrode 17 is illustrated in Table 2 below.

[Table 2]
Voltage applied to cathode electrode V _C = 0 volts Voltage applied to gate electrode V _G = 30 to 35 volts Voltage applied to focusing electrode V _F = 40 to 70 volts Voltage applied to anode electrode V _A = 0 kilovolt

By applying a voltage to each of the electrodes 11, 13, 17, electrons are emitted from the electron emission portions 15, 15 A, and the electrons collide with the convergence electrode 17. Due to the collision of the electrons with the focusing electrode 17, the gas [for example, oxygen gas (O ₂ ), hydrogen gas (H ₂ ), methane gas (CH ₄ ), carbon monoxide gas (CO), carbon dioxide gas is emitted from the focusing electrode 17. (CO ₂ )] is released, and among these gases, a gas having an oxidizing action is adsorbed on the antistatic film 41. Even if the antistatic film 41 is in a reduced state due to the collision of some of the backscattered electrons from the phosphor layer 22 with the spacer 40 (more specifically, the antistatic film 41). Since the antistatic film 41 is oxidized again by this gas, the electric resistance value of the antistatic film 41 is changed to a state before the antistatic film 41 is reduced (or a state before the antistatic film 41 is reduced). Can be restored (corrected). Therefore, the electric field is not disturbed in the vicinity of the spacer 40, the trajectory of the electron beam in one subpixel located in the vicinity of the spacer 40 varies and changes, and the electron beam arrival position in the opposing phosphor layer 22 changes. Therefore, it is possible to prevent the occurrence of a problem that the image quality of the display device deteriorates.

  A display device was prototyped, and the display device was actually operated for a predetermined time under the conditions shown in Table 3 below.

[Table 3]
Voltage applied to the anode electrode V _A = 9 kilovolts Voltage applied to the cathode electrode V _C = 0 volts Voltage applied to the gate electrode V _G = 30 to 35 volts Voltage applied to the converging electrode V _F = 0 volts

  In the subpixel adjacent to the spacer 40, when the actual operation starts, the electron beam emitted from the electron emission area EA collides with the phosphor layer 22 facing the electron emission area EA (the center of gravity of the electron beam (fluorescence). The point at which the body layer 22 shines brightest) was taken as the origin. Then, after the elapse of a predetermined actual operation time (application time), the center of gravity of the electron beam when the electron beam emitted from the electron emission area EA collides with the phosphor layer 22 facing the electron emission area EA. The distance from the point to the above-described origin (in Table 4, indicated by “pre-correction distance”) was measured.

  Subsequently, the voltage shown in Table 2 was applied to each electrode 11, 13, 17, 24 for 1 hour. Thereafter, the voltage shown in Table 3 is applied again to each of the electrodes 11, 13, 17, and 24, and the electron beam emitted from the electron emission area EA again and the phosphor layer 22 facing the electron emission area EA The distance from the center of gravity of the electron beam at the time of collision to the above-described origin (in Table 4, indicated by “corrected distance”) was measured.

  The measurement results are shown in Table 4 below. The unit of the distance before correction and the distance after correction is “μm”.

[Table 4]
Measurement point Distance before correction Distance after correction 1 22.2 1.0
2 12.8 -0.9
3 12.8 -0.2
4 12.3 0.8
5 11.3 0.3
6 12.4 0.4
7 13.7 1.3
8 7.5 -0.8
9 7.0 -0.5
10 3.8 -1.1
11 5.1 -0.3
12 5.2 -0.7

  From Table 4, by executing the antistatic film property maintaining method of Example 1, the trajectory of the electron beam in one subpixel located in the vicinity of the spacer 40 is returned to a state close to the state at the start of actual operation (correction). You can).

  Hereinafter, with reference to FIGS. 10A and 10B and FIGS. 11A and 11B, which are schematic partial end views of the support and the like, a method for assembling the display device of Example 1 will be described below. Will be explained.

  First, for example, a Spindt-type field emission device is manufactured. This Spindt-type field emission device can be basically obtained by a method of forming the conical electron emission portion 15 by vertical vapor deposition of a metal material. That is, the vapor deposition particles are perpendicularly incident on the second opening 14B provided in the gate electrode 13, but use the shielding effect by the overhanging deposit formed near the opening end of the second opening 14B. Then, the amount of vapor deposition particles reaching the bottom of the third opening 14C is gradually reduced, and the electron emission portion 15 that is a conical deposit is formed in a self-aligning manner. Here, a method for forming the separation layer 18 in advance on the convergence electrode 17, the gate electrode 13, and the first insulating layer 12 in order to facilitate removal of unnecessary overhanging deposits will be described. In the drawings for explaining the manufacturing method of the field emission device, only one field emission device is shown for convenience.

[Step-100]
Specifically, first, a cathode electrode conductive material layer made of, for example, polysilicon is formed on the support 10 made of, for example, a glass substrate by a plasma CVD method, and then the cathode is formed based on the lithography technique and the dry etching technique. The conductive material layer for electrodes is patterned to form a strip-like cathode electrode 11. Thereafter, a first insulating layer 12 made of SiO _{2 is} formed on the entire surface by a CVD method.

[Step-110]
Next, a gate electrode conductive material layer (for example, a chromium layer) is formed on the first insulating layer 12 by a sputtering method, and then the gate electrode conductive material layer is patterned by a lithography technique and a dry etching technique. By doing so, a strip-like gate electrode 13 made of chromium (Cr) can be obtained. The strip-shaped cathode electrode 11 extends in the left-right direction in the drawing, and the strip-shaped gate electrode 13 extends in the direction perpendicular to the drawing.

  The gate electrode 13 is formed by a well-known thin film formation method such as a PVD method such as a vacuum deposition method, a CVD method, a plating method such as an electroplating method or an electroless plating method, a screen printing method, a laser ablation method, a sol-gel method, a lift-off method. If necessary, it may be formed by a combination with an etching technique. According to the screen printing method or the plating method, for example, a strip-shaped gate electrode can be directly formed.

[Step-120]
Thereafter, a second insulating layer 16 made of polyimide resin is further provided on the gate electrode 13 and the first insulating layer 12, and a focusing electrode 17 is provided on the second insulating layer 16. Specifically, for example, the second insulating layer 16 provided with the first opening 14A can be obtained by forming a photosensitive polyimide resin on the entire surface and exposing, developing, and baking the photosensitive polyimide resin. it can. Thereafter, a focusing electrode 17 made of aluminum (Al) is formed on the second insulating layer 16 by an oblique vacuum deposition method while rotating the support 10. The focusing electrode 17 extends to the upper side surface of the first opening 14A. Next, a resist layer is provided, a second opening 14B is formed in the gate electrode 13 by etching, a third opening 14C is formed in the first insulating layer 12, and a cathode electrode is formed at the bottom of the third opening 14C. After exposing 11, the resist layer is removed. Thus, the structure shown in FIG. 10A can be obtained.

[Step-130]
Next, while rotating the support 10, nickel (Ni) is obliquely vacuum-deposited on the first insulating layer 12 including the gate electrode 13 and the focusing electrode 17, thereby forming the release layer 18 (see FIG. 10 (B)). At this time, by selecting a sufficiently large incident angle of the vapor deposition particles with respect to the normal of the support 10 (for example, an incident angle of 65 to 85 degrees), nickel is hardly deposited on the bottom of the third opening 14C. A release layer 18 can be formed on the focusing electrode 17, the gate electrode 13, and the first insulating layer 12. The release layer 18 protrudes in a bowl shape from the opening end of the second opening 14B, whereby the diameter of the second opening 14B is substantially reduced.

[Step-140]
Next, for example, molybdenum (Mo) is vertically deposited as an electrically conductive material on the entire surface (incident angle: 3 to 10 degrees). At this time, as shown in FIG. 11A, as the conductive material layer 19 having an overhang shape grows on the release layer 18, the substantial diameter of the second opening 14B is gradually reduced. The vapor deposition particles that contribute to the deposition at the bottom of the third opening 14C are gradually limited to those that pass near the center of the second opening 14B. As a result, a conical deposit is formed at the bottom of the third opening 14 </ b> C, and this conical deposit becomes the electron emission portion 15.

[Step-150]
Thereafter, the peeling layer 18 is peeled off from the surfaces of the focusing electrode 17, the gate electrode 13 and the first insulating layer 12 by a lift-off method, and the conductive material layer 19 above the focusing electrode 17, the gate electrode 13 and the first insulating layer 12 is removed. Selectively remove. Next, it is preferable that the side wall surface of the third opening 14 </ b> C provided in the first insulating layer 12 is retracted by isotropic etching from the viewpoint of exposing the opening end of the gate electrode 13. The isotropic etching can be performed by dry etching using radicals as a main etching species, such as chemical dry etching, or wet etching using an etchant. As the etchant, for example, a 1: 100 (volume ratio) mixed solution of 49% hydrofluoric acid aqueous solution and pure water can be used. In this way, a Spindt field emission device having the structure shown in FIG. 11B can be obtained.

  In this manner, a cathode panel CP in which a plurality of field emission devices are formed on the support 10 can be obtained. On the other hand, an anode panel AP in which the phosphor layer 22, the anode electrode 24 and the like are formed on the substrate 20 is prepared based on a known method.

[Step-160]
Then, the display device is assembled. Specifically, the spacer 40 is attached to the spacer holding part 25 provided in the effective area of the anode panel AP, and the anode panel AP and the cathode panel CP are arranged so that the phosphor layer 22 and the electron emission area EA face each other. Then, the anode panel AP and the cathode panel CP (more specifically, the substrate 20 and the support body 10) are joined together at the peripheral edge via a frame body 26 made of ceramics or glass. At the time of joining, frit glass is applied to the joining portion between the frame body 26 and the anode panel AP and the joining portion between the frame body 26 and the cathode panel CP, and the anode panel AP, the cathode panel CP, and the frame body 26 are pasted. In addition, the frit glass is dried by preliminary baking, and then main baking is performed at about 450 ° C. for 10 to 30 minutes. Thereafter, the space surrounded by the anode panel AP, the cathode panel CP, the frame body 26, and the frit glass (not shown) is exhausted through a through hole (not shown) and a tip tube (not shown), and the pressure of the space When the ^pressure reaches about 10 ⁻⁵ Pa, the tip tube is sealed by heating and melting. In this way, the space surrounded by the anode panel AP, the cathode panel CP, and the frame 26 can be evacuated.

  Alternatively, for example, the frame, the anode panel AP, and the cathode panel CP may be bonded together in a high vacuum atmosphere. Alternatively, depending on the structure of the display device, the anode panel AP and the cathode panel CP may be bonded together by using only an adhesive layer without a frame. Thereafter, wiring connection with necessary external circuits is performed, and the display device of Example 1 is completed.

  As mentioned above, although this invention was demonstrated based on the preferable Example, this invention is not limited to this Example. The configurations and structures of the cold cathode field emission display, cathode panel and anode panel, and cold cathode field emission device described in the embodiments are examples, and can be changed as appropriate. The manufacturing method of the cathode field emission display device and the cold cathode field emission device is also an example, and can be appropriately changed. Furthermore, various materials used in the manufacture of the anode panel and the cathode panel are also examples, and can be changed as appropriate. In the cold cathode field emission display, the color display has been described as an example, but a single color display may be used.

  In the field emission device, the configuration in which one electron emission portion corresponds to one third opening has been described. However, depending on the structure of the field emission device, a plurality of electron emission portions may be provided in one third opening. Or a configuration in which one electron emission portion corresponds to a plurality of third openings. Alternatively, the gate electrode is provided with a plurality of second openings, the plurality of third openings connected to the plurality of second openings of the first insulating layer is provided, and one or a plurality of electron emission portions are provided. You can also

The focusing electrode is not only formed by the method described in the first embodiment, but, for example, an insulating film made of, for example, SiO _{2 is} formed on both surfaces of a metal plate made of 42% Ni—Fe alloy having a thickness of several tens of μm. After the formation, the converging electrode can be manufactured by forming the first opening by punching or etching the region corresponding to each pixel. Then, by stacking the cathode panel, the metal plate, and the anode panel, arranging the frame on the outer periphery of both panels, and performing heat treatment, the insulating film and the first insulating layer 12 formed on one surface of the metal plate. Are bonded to each other, the insulating film formed on the other surface of the metal plate and the anode panel AP are bonded, these members are integrated, and then vacuum-encapsulated, whereby the cold cathode field emission display device is obtained. It can also be completed.

FIG. 1 is a conceptual partial end view of a cold cathode field emission display having a Spindt type cold cathode field emission device. FIG. 2 is a schematic exploded perspective view of a part of the cathode panel and the anode panel when the cathode panel and the anode panel constituting the cold cathode field emission display device are disassembled. FIG. 3 is a conceptual partial end view of a cold cathode field emission display having a flat type cold cathode field emission device. FIG. 4 is a layout diagram schematically showing the layout of barrier ribs, spacers, and phosphor layers in an anode panel constituting a cold cathode field emission display. FIG. 5 is a layout diagram schematically showing the layout of the barrier ribs, spacers, and phosphor layers in the anode panel constituting the cold cathode field emission display. FIG. 6 is an arrangement diagram schematically showing the arrangement of the barrier ribs, spacers and phosphor layers in the anode panel constituting the cold cathode field emission display. FIG. 7 is a layout diagram schematically showing the layout of the barrier ribs, spacers, and phosphor layers in the anode panel constituting the cold cathode field emission display. FIG. 8 is a layout diagram schematically showing the layout of the barrier ribs, spacers, and phosphor layers in the anode panel constituting the cold cathode field emission display. FIG. 9 is a layout diagram schematically showing the layout of barrier ribs, spacers, and phosphor layers in an anode panel constituting a cold cathode field emission display. 10A and 10B are schematic partial end views of a support and the like for explaining a method of manufacturing a Spindt-type cold cathode field emission device. (A), (B), and (C) of FIG. 11 are schematic partial views of a support and the like for explaining a method of manufacturing a Spindt-type cold cathode field emission device, following (B) of FIG. It is an end view. FIG. 12 is a diagram schematically showing the trajectory of the electron beam in the vicinity of the spacer. FIG. 13 is a diagram schematically showing the trajectory of the electron beam in the vicinity of the spacer.

Explanation of symbols

AP ... anode panel, CP ... cathode panel, EA ... electron emission region, 10 ... support, 11 ... cathode electrode, 12 ... first insulating layer, 13 ... gate Electrode, 14A ... 1st opening, 14B ... 2nd opening, 14C ... 3rd opening, 15, 15A ... Electron emission part, 16 ... 2nd insulating layer, 17 * ..Converging electrode, 18 ... peeling layer, 19 ... conductive material layer, 20 ... substrate, 21 ... partition, 22, 22R, 22G, 22B ... phosphor layer, 23 ... Light absorption layer (black matrix), 24... Anode electrode, 25... Spacer holding part, 26... Frame, 31. ... Converging electrode control circuit, 34 ... Anode electrode control circuit, 40 ... Pacer, 41 ... antistatic film

Claims (4)

A cathode panel provided with a plurality of cold cathode field emission devices and an anode panel provided with a phosphor layer and an anode electrode are joined together via a frame at the periphery thereof.
The space between the cathode panel and the anode panel is in a vacuum state,
Between the cathode panel and the anode panel, a plurality of spacers having an antistatic film formed on the surface are disposed,
Cold cathode field emission device
(A) a cathode electrode formed on a support;
(B) a first insulating layer formed on the support and the cathode electrode;
(C) a gate electrode formed on the first insulating layer;
(D) a second insulating layer formed on the gate electrode and the first insulating layer;
(E) a focusing electrode formed on the second insulating layer;
(F) a first opening formed in the focusing electrode and the second insulating layer; a second opening formed in the gate electrode and communicating with the first opening; and a second opening formed in the first insulating layer. A third opening communicating with the part, and
(G) an electron emission portion formed on the cathode electrode exposed at the bottom of the third opening,
A cold cathode field emission display comprising a,
With no voltage applied to the anode electrode, a voltage higher than the voltage applied to the cathode electrode is applied to the gate electrode, and a voltage higher than the voltage applied to the gate electrode is applied to the converging electrode to emit from the electron emitter. electrons to collide with the focusing electrode, the cold cathode field emission display antistatic film Rukoto adsorbed onto the antistatic layer of the gas to be oxidized with the released oxidizing action from the focusing electrode. 2. The cold cathode field emission display according to claim 1, wherein the focusing electrode is made of an aluminum thin film formed by a vacuum deposition method . Antistatic film, a cold cathode field emission display according to claim 1 comprising a metal oxide. Antistatic film, a cold cathode field emission display according to claim 3 consisting of chromium oxide.

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